Synthesis scales refer to the amount of starting material present, not the amount of final product produced. This is the same for all manufacturers of synthetic DNA. When a 50 nmole scale synthesis is specified, approximately 50 nmoles of the first base is added to the DNA synthesizer. For an average 25-mer, at least 25% of this starting material will result in failure sequences, hence it is not possible to produce 50 nmoles of full-length product from a 50 nmole scale synthesis. In addition, further losses occur during processing, transfer of material, and quality control.

Estimated nmole Yield
The table below shows estimated nmole yield for desalted oligos at the various starting synthesis scales. This table converts the OD units into nmole values for an oligo with an equal and even distribution of each base. The actual nmol conversion from OD for a specific oligo may be different based on the composition and distribution of each base within the oligo.

Approximate nmole Ending Yield at Each Starting Synthesis Scale

Oligo Length 25nmole (2OD) 50nmole (4OD) 200nmole (16OD)
20 10 20 80
25 8 16 64
30 6.6 13.2 52.8
35 5.6 11.2 44.8
40 5 10 40
45 4.5 9 36
50 4 8 32
60 3.2 6.4 25.6
70 2.8 5.6 22.4
80 2.4 4.8 19.2

Minimum Yields
When ordering custom oligos, remember that the scale of synthesis (25 nmol, 50 nmol, 200 nmol, 1 µmol, or 10 µmol) is the starting point for synthesis, not the guaranteed final amount. Oligonecleotide length, sequence, GC content, and coupling efficiencies can vary the yield of nmole amounts post-synthesis. Invitrogen guarantees the total yield of oligonucleotide as a minimum number of OD units. Purification by HPLC, PAGE, and Cartridge will also affect final product yield.

The table below shows minimum guarantee yields (OD260). Please note that OD guarantee is valid for unmodified oligos 20 to 100 bases in length.

Yields for oligos under 20 bases are not guaranteed. In general they are about half of the values as shown in the table below.

BASES SCALE DESALTED (OD) CARTRIDGE (OD) HPLC (OD) PAGE (OD)
>20mer25 nmole 2 n/a n/a n/a
50 nmole 4 2 1 0.5
200 nmole 16 10 3 1
1 µmole 50 25 15 5
10 µmole 500 n/a 150 50